Thank you Tom! Judging from the serial number, I have a 1981. The lens screws on to the camera fine, and the focus ring and f stops are smooth too. When the lens is on the Bessa R the markings are on the bottom and I can't focus the lens in the rangefinder patch. I guess like the MIR lens, The body/lens don't match up. I did a Google search and found a site which indicated they'd be OK-just couldn't close focus..Oh well, I'll give it a try this weekend.